This application is for partial funding of a FASEB Summer Conference on Lung Surfactant: Cellular and Molecular Biology to be held July 24 - 29, 2004 at The Vermont Academy, Saxtons River, VT. Attendance is limited to 160 persons to create a climate conducive to interaction. The overall objective of this conference is to provide a forum for exchange of new and cutting-edge information regarding the basic molecular and cellular biology of fetal lung development and differentiation of surfactant producing cells, mechanisms in the regulation of synthesis, trafficking and secretion of surfactant lipids and proteins. The role of surfactant proteins as components of the innate immune system will be considered, as well as their novel roles in mammalian physiology and the relationship of their structure to function. The conference also will emphasize the pathophysiology of the surfactant system, with regard to protein misfolding and disease, lung injury and repair. We believe that this meeting is unique and highly important because, in addition to inviting speakers who are recognized experts in the surfactant field, we have included renowned experts working in different but related disciplines to provide in-depth information in the areas of stem cell biology and organogenesis, protein misfolding, organelle biogenesis and trafficking and host defense. The topics considered in this conference include: (1) regulation of stem cell fate, origin of lung stem cells, mechanisms in differentiation of surfactant-producing cells, and in type II cell to type I cell transdifferentiation; (2) transcriptional mechanisms involved in organogenesis, cellular differentiation and specialized function of alveolar epithelial cells; (3) organelle biogenesis and exocytosis of surfactant lipids and proteins by type II cells; (4) role of surfactant protein folding in trafficking and pathophysiology; (5) regulation of surfactant homeostasis and mechanisms involved in the pathophysiology of this process; (6) roles of surfactant proteins A and D as components of the innate immune system within the lung alveolus; (7) structural analysis of the surfactant proteins and relationship of protein structure to function; (8) mechanisms of lung injury and results of clinical trials evaluating treatment regimens for adult respiratory distress syndrome. A major goal of this conference is to create a forum to disseminate new information and promote the interaction of established and junior investigators in the surfactant field with outstanding scientists of different backgrounds and areas of expertise. We believe that this meeting will provide a framework for novel approaches and directions for future research in the surfactant field.